There are programs that capture data from packets as they travel over the network. These programs are called packet sniffers. The packet sniffer can grab data, such as user names, passwords, and proprietary information that travels unencrypted over the network. Intruders can launch widespread attacks on systems, using passwords captured by the sniffer. Using a sniffer without proper authority can violate the wiretap statute. A system or network administrator could use a packet sniffer for security purposes. It is important to note that sniffers are also used by government investigators to conduct content monitoring. Such uses must conform to the Federal Wiretap Act, the Electronic Communications Privacy Act, and other applicable law.